Rad light coming on?
 

Hey guys! Finally got my FC over from Japan, and road certified! Will get you all some new pics of her when I get a chance!! Quick question!!

The rad light on the dash keeps coming on, the temp gauge stays bang on in the middle, and it doesn't overflow. The light will come on, than go out, and come on. Fan seems to be working, coolant passed testing and is crystal clean, i changed the thremostat, and rad cap already in case that was it. Rad is clear of crap. Other than the light, it seems to be running fine. Just a faulty sensor?

You've bled the cooling system properly (coolant bleed screw at the top of the radiator top outlet), and there's no air AT ALL in the radiator when you pull the cap off?

If so, then you probably should replace the sending unit. You don't want to disable this system.

-=Russ=-

yea I bled the system completely dry.

Somemore stuff happened. So driving the car to work(like 8 minute drive max) and the gauge spikes to 3/4 than comes down to 1/2, than a few seconds later spikes up again. I get to work and pop the hood, the rad and fluid(that is now in the resevoir) is bone cold, yet it reads hot on the guage. Mechanic at work thinks it is a faulty thermostat. So i ordered a OE one. Also is a 195 degree to high for the car? Water pump possibly? Car runs super solid other than this, no white smoke, starts good, and runs real strong.

Buy-Order the OME from your Mazda dealer, + a new gasket.
195 is not OE or the right thermostat. The auto parts store says it's OME but it's not!
180 is stock with a 'jiggle pin'. Mazda part number - 8AF1-15-171-9U (at least for my 86-NA)
Install the new thermo with the jiggle pin as close to the top of the water pump housing as possible. Usualy a 10 or 2 o'clock position. If it doesnt have a jiggle pin, dont put it in, or, if in doubt , take it out. lol
Overall, it does sound like the mechanic @work is right and whatever thermo may be in you car is wacky.
My car did some similar things with-out a thermo installed. I assumed it had one but was wrong. Car runs differently now to say the least.

yea got the new thermo today! I know the other one did not have a pin so that is definately the problem or was. car now developed a small leak out of the rad... so that just means i need a koyo ;) so its ordered now to... Gonna have an entire new cooling system now in the car so that will solve all issues.